Randomization procedure for assigning interference measurement resources in wireless communication

ABSTRACT

Methods and apparatus are provided for assigning interference measurement resources. A method includes receiving at least one identifier, which determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource. The at least one interference measurement resource comprises a number of resource elements out of a set of resource elements. The method also includes measuring interference based at least in part on the at least one interference measurement resource.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.13/781,605, filed Feb. 28, 2013, which claims priority to ProvisionalApplication No. 61/707,855, filed Sep. 28, 2012, entitled “RANDOMIZATIONPROCEDURE FOR ASSIGNING INTERFERENCE MANAGEMENT RESOURCES IN LTE”, bothof which are assigned to the assignee hereof, and are hereby expresslyincorporated in their entirety by reference herein.

FIELD

The present disclosure relates to communication systems and totechniques for assigning interference measurement resources in wirelesscommunication.

BACKGROUND

Wireless communication networks are widely deployed to provide variouscommunication content such as voice, video, packet data, messaging,broadcast, etc. These wireless networks may be multiple-access networkscapable of supporting multiple users by sharing the available networkresources. Examples of such multiple-access networks include CodeDivision Multiple Access (CDMA) networks, Time Division Multiple Access(TDMA) networks, Frequency Division Multiple Access (FDMA) networks,Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA)networks.

A wireless communication network may include a number of base stationsthat can support communication for a number of mobile entities, such as,for example, user equipments (UEs). A UE may communicate with a basestation via the downlink (DL) and uplink (UL). The DL (or forward link)refers to the communication link from the base station to the UE, andthe UL (or reverse link) refers to the communication link from the UE tothe base station.

The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE)represents a major advance in cellular technology as an evolution ofGlobal System for Mobile communications (GSM) and Universal MobileTelecommunications System (UMTS). The LTE physical layer (PHY) providesa highly efficient way to convey both data and control informationbetween base stations, such as an evolved Node Bs (eNBs), and mobileentities, such as UEs.

In recent years, users have started to replace fixed line broadbandcommunications with mobile broadband communications and haveincreasingly demanded great voice quality, reliable service, and lowprices, especially at their home or office locations. In order toprovide indoor services, network operators may deploy differentsolutions. For networks with moderate traffic, operators may rely onmacro cellular base stations to transmit the signal into buildings.However, in areas where building penetration loss is high, it may bedifficult to maintain acceptable signal quality, and thus othersolutions are desired. New solutions are frequently desired to make thebest of the limited radio resources such as space and spectrum.

SUMMARY

Methods and apparatus for assigning interference measurement resourcesare described in detail in the detailed description, and certain aspectsare summarized below. This summary and the following detaileddescription should be interpreted as complementary parts of anintegrated disclosure, which parts may include redundant subject matterand/or supplemental subject matter. An omission in either section doesnot indicate priority or relative importance of any element described inthe integrated application. Differences between the sections may includesupplemental disclosures of alternative embodiments, additional details,or alternative descriptions of identical embodiments using differentterminology, as should be apparent from the respective disclosures.

In an aspect, a method of wireless communication includes receiving atleast one identifier wherein the at least one identifier determines, atleast in part, at least one interference measurement resource thatpartially overlaps with another at least one interference measurementresource, wherein the at least one interference measurement resourcecomprises a number of resource elements out of a set of resourceelements. The method includes measuring interference based at least inpart on the at least one interference measurement resource.

In another aspect, a wireless communication apparatus includes at leastone processor configured to (a) receive at least one identifier whereinthe at least one identifier determines, at least in part, at least oneinterference measurement resource that partially overlaps with anotherat least one interference measurement resource, wherein the at least oneinterference measurement resource comprises a number of resourceelements out of a set of resource elements, and (b) measure interferencebased at least in part on the at least one interference measurementresource. The wireless communication apparatus includes a memory coupledto the at least one processor for storing data.

In another aspect, a wireless communication apparatus includes means forreceiving at least one identifier wherein the at least one identifierdetermines, at least in part, at least one interference measurementresource that partially overlaps with another at least one interferencemeasurement resource, wherein the at least one interference measurementresource comprises a number of resource elements out of a set ofresource elements. The wireless communication apparatus includes meansfor measuring interference based at least in part on the at least oneinterference measurement resource.

In another aspect, a computer program product includes acomputer-readable medium including code for causing at least onecomputer to receive at least one identifier wherein the at least oneidentifier determines, at least in part, at least one interferencemeasurement resource that partially overlaps with another at least oneinterference measurement resource, wherein the at least one interferencemeasurement resource includes a number of resource elements out of a setof resource elements. The computer-readable medium includes code forcausing the at least one computer to measure interference based at leastin part on the at least one interference measurement resource.

In another aspect, a method of wireless communication includestransmitting an identifier of a network entity to at least one mobileentity, the identifier determining, at least in part, at least oneinterference measurement resource that partially overlaps with anotherat least one interference measurement resource, wherein the at least oneinterference measurement resource comprises a number of resourceelements out of a set of resource elements. The method includesreceiving channel state information (CST) reports from at least onemobile entity based on the at least one interference measurementresource.

In another aspect, a wireless communication apparatus includes at leastone processor configured to (a) transmit an identifier of a networkentity to at least one mobile entity, the identifier determining, atleast in part, at least one interference measurement resource thatpartially overlaps with another at least one interference measurementresource, wherein the at least one interference measurement resourcecomprises a number of resource elements out of a set of resourceelements, and (b) receive channel state information (CSI) reports fromat least one mobile entity based on the at least one interferencemeasurement resource. The wireless communication apparatus includes amemory coupled to the at least one processor for storing data.

In another aspect, a wireless communication apparatus includes means fortransmitting an identifier of a network entity to at least one mobileentity, the identifier determining, at least in part, at least oneinterference measurement resource that partially overlaps with anotherat least one interference measurement resource, wherein the at least oneinterference measurement resource comprises a number of resourceelements out of a set of resource elements. The wireless communicationapparatus includes means for receiving channel state information (CSI)reports from at least one mobile entity based on the at least oneinterference measurement resource.

In another aspect, a computer program product includes acomputer-readable medium comprising code for causing at least onecomputer to transmit an identifier of a network entity to at least onemobile entity, the identifier determining, at least in part, at leastone interference measurement resource that partially overlaps withanother at least one interference measurement resource, wherein the atleast one interference measurement resource comprises a number ofresource elements out of a set of resource elements. Thecomputer-readable medium includes code for causing the at least onecomputer to receive channel state information (CSI) reports from atleast one mobile entity based on the at least one interferencemeasurement resource.

It is understood that other aspects will become readily apparent tothose skilled in the art from the following detailed description,wherein it is shown and described various aspects by way ofillustration. The drawings and detailed description are to be regardedas illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram conceptually illustrating an example of atelecommunications system.

FIG. 2 is a block diagram conceptually illustrating an example of a downlink frame structure in a telecommunications system.

FIG. 3 is a block diagram conceptually illustrating a design of a basestation/eNB and a UE.

FIGS. 4A-C illustrate resource element assignments using a two Stageprocess.

FIGS. 5A-B illustrate resource element assignments for two cells.

FIG. 5C illustrates possible overlap in resource element assignments forthe two cells.

FIGS. 5D-E illustrate different overlapping scenarios for resourceelement assignments for two cells.

FIG. 6 illustrates an exemplary methodology for measuring interferenceresources.

FIG. 7 illustrates an exemplary methodology for assigning interferencemeasurement resources.

FIG. 8 shows an embodiment of an apparatus for measuring interferenceresources, in accordance with the methodology of FIG. 6.

FIG. 9 shows an embodiment of an apparatus for assigning interferencemeasurement resources, in accordance with the methodology of FIG. 7.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to represent the only configurationsin which the concepts described herein may be practiced. The detaileddescription includes specific details for the purpose of providing athorough understanding of the various concepts. However, it will beapparent to those skilled in the art that these concepts may bepracticed without these specific details. In some instances, well-knownstructures and components are shown in block diagram form in order toavoid obscuring such concepts.

The techniques described herein may be used for various wirelesscommunication networks such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA andother networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA, cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA network may implement aradio technology such as Global System for Mobile Communications (GSM).An OFDMA network may implement a radio technology such as Evolved UTRA(E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part ofUniversal Mobile Telecommunication System (UMTS). 3GPP Long TermEvolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS thatuse E-UTRA. UTRA, E-UTRA, UMTS. LTE, LTE-A and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). CDMA2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the wireless networks andradio technologies mentioned above as well as other wireless networksand radio technologies. For clarity, certain aspects of the techniquesare described below for LTE, and LTE terminology is used in much of thedescription below.

FIG. 1 shows a wireless communication network 100, which may be an LTEnetwork. The wireless network 100 may include a number of eNBs 110 andother network entities. An eNB may be a station that communicates withthe UEs and may also be referred to as a base station, a Node B, anaccess point, or other term. Each eNB 110 a, 110 b, 110 c may providecommunication coverage for a particular geographic area. In 3GPP, theterm “cell” can refer to a coverage area of an eNB and/or an eNBsubsystem serving this coverage area, depending on the context in whichthe term is used.

An eNB may provide communication coverage for a macro cell, a pico cell,a femto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a Closed Subscriber Group (CSG). UEs for users in the home,etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNBfor a pico cell may be referred to as a pico eNB. An eNB for a femtocell may be referred to as a femto eNB or a home eNB (HNB). In theexample shown in FIG. 1, the eNBs 110 a, 110 b and 110 c may be macroeNBs for the macro cells 102 a, 102 b and 102 c, respectively. The eNB110 x may be a pico eNB for a pico cell 102 x. The eNBs 110 y and 110 zmay be femto eNBs for the femto cells 102 y and 102 z, respectively. AneNB may support one or multiple (e.g., three) cells.

The wireless network 100 may also include relay stations 110 r. A relaystation is a station that receives a transmission of data and/or otherinformation from an upstream station (e.g., an eNB or a UE) and sends atransmission of the data and/or other information to a downstreamstation (e.g., a UE or an eNB). A relay station may also be a UE thatrelays transmissions for other UEs. In the example shown in FIG. 1, arelay station 110 r may communicate with the eNB 110 a and a UE 120 r inorder to facilitate communication between the eNB 110 a and the UE 120r. A relay station may also be referred to as a relay eNB, a relay, etc.

The wireless network 100 may be a heterogeneous network that includeseNBs of different types, e.g., macro eNBs, pico eNBs, femto eNBs,relays, etc. These different types of eNBs may have different transmitpower levels, different coverage areas, and different impact oninterference in the wireless network 100. For example, macro eNBs mayhave a high transmit power level (e.g., 20 Watts) whereas pico eNBs,femto eNBs and relays may have a lower transmit power level (e.g., 1Watt).

The wireless network 100 may support synchronous or asynchronousoperation. For synchronous operation, the eNBs may have similar frametiming, and transmissions from different eNBs may be approximatelyaligned in time. For asynchronous operation, the eNBs may have differentframe timing, and transmissions from different eNBs may not be alignedin time. The techniques described herein may be used for bothsynchronous and asynchronous operation.

A network controller 130 may couple to a set of eNBs and providecoordination and control for these eNBs. The network controller 130 maycommunicate with the eNBs 110 via a backhaul. The eNBs 110 may alsocommunicate with one another, e.g., directly or indirectly via wirelessor wireline backhaul.

The UEs 120 may be dispersed throughout the wireless network 100, andeach UE may be stationary or mobile. A UE may also be referred to as aterminal, a mobile station, a subscriber unit, a station, etc. A UE maybe a cellular phone, a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, orother mobile entities. A UE may be able to communicate with macro eNBs,pico eNBs, femto eNBs, relays, or other network entities. In FIG. 1, asolid line with double arrows indicates desired transmissions between aUE and a serving eNB, which is an eNB designated to serve the UE on thedownlink and/or uplink. A dashed line with double arrows indicatesinterfering transmissions between a UE and an eNB.

LTE utilizes orthogonal frequency division multiplexing (OFDM) on thedownlink and single-carrier frequency division multiplexing (SC-FDM) onthe uplink. OFDM and SC-FDM partition the system bandwidth into multiple(K) orthogonal subcarriers, which are also commonly referred to astones, bins, etc. Each subcarrier may be modulated with data. Ingeneral, modulation symbols are sent in the frequency domain with OFDMand in the time domain with SC-FDM. The spacing between adjacentsubcarriers may be fixed, and the total number of subcarriers (K) may bedependent on the system bandwidth. For example, K may be equal to 128,256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10 or 20megahertz (MHz), respectively. The system bandwidth may also bepartitioned into subbands. For example, a subband may cover 1.08 MHz,and there may be 1, 2, 4, 8 or 16 subbands for system bandwidth of 1.25,2.5, 5, 10 or 20 MHz, respectively.

FIG. 2 shows a down link frame structure used in LTE. The transmissiontimeline for the downlink may be partitioned into units of radio frames.Each radio frame, for example, frame 202, may have a predeterminedduration (e.g., 10 milliseconds (ms)) and may be partitioned into 10subframes 204 with indices of 0 through 9. Each subframe, for example‘Subframe 0’ 206, may include two slots, for example, ‘Slot 0’ 208 and‘Slot 1’ 210. Each radio frame may thus include 20 slots with indices of0 through 19. Each slot may include L symbol periods, e.g., 7 symbolperiods 212 for a normal cyclic prefix (CP), as shown in FIG. 2, or 6symbol periods for an extended cyclic prefix. The normal CP and extendedCP may be referred to herein as different CP types. The 2L symbolperiods in each subframe may be assigned indices of 0 through 2L−1. Theavailable time frequency resources may be partitioned into resourceblocks. Each resource block may cover N subcarriers (e.g., 12subcarriers) in one slot.

In LTE, an eNB may send a primary synchronization signal (PSS) and asecondary synchronization signal (SSS) for each cell in the eNB. Theprimary and secondary synchronization signals may be sent in symbolperiods 6 and 5, respectively, in each of subframes 0 and 5 of eachradio frame with the normal cyclic prefix, as shown in FIG. 2. Thesynchronization signals may be used by UEs for cell detection andacquisition. The eNB may send a Physical Broadcast Channel (PBCH) insymbol periods 0 to 3 in slot 1 of subframe 0. The PBCH may carrycertain system information.

The eNB may send a Physical Control Format Indicator Channel (PCFICH) inonly a portion of the first symbol period of each subframe, althoughdepicted in the entire first symbol period 214 in FIG. 2. The PCFICH mayconvey the number of symbol periods (M) used for control channels, whereM may be equal to 1, 2 or 3 and may change from subframe to subframe. Mmay also be equal to 4 for a small system bandwidth. e.g., with lessthan 10 resource blocks. In the example shown in FIG. 2, M=3. The eNBmay send a Physical HARQ Indicator Channel (PHICH) and a PhysicalDownlink Control Channel (PDCCH) in the first M symbol periods of eachsubframe (M=3 in FIG. 2). The PHICH may carry information to supporthybrid automatic retransmission (HARQ). The PDCCH may carry informationon resource allocation for UEs and control information for downlinkchannels. Although not shown in the first symbol period in FIG. 2, it isunderstood that the PDCCH and PHICH are also included in the firstsymbol period. Similarly, the PHICH and PDCCH are also both in thesecond and third symbol periods, although not shown that way in FIG. 2.The eNB may send a Physical Downlink Shared Channel (PDSCH) in theremaining symbol periods of each subframe. The PDSCH may carry data forUEs scheduled for data transmission on the downlink. The various signalsand channels in LTE are described in 3GPP TS 36.211, entitled “EvolvedUniversal Terrestrial Radio Access (E-UTRA); Physical Channels andModulation,” which is publicly available.

The eNB may send the PSS, SSS and PBCH in the center 1.08 MHz of thesystem bandwidth used by the eNB. The eNB may send the PCFICH and PHICHacross the entire system bandwidth in each symbol period in which thesechannels are sent. The eNB may send the PDCCH to groups of UEs incertain portions of the system bandwidth. The eNB may send the PDSCH tospecific UEs in specific portions of the system bandwidth. The eNB maysend the PSS, SSS, PBCH, PCFICH and PHICH in a broadcast manner to allUEs, may send the PDCCH in a unicast manner to specific UEs, and mayalso send the PDSCH in a unicast manner to specific UEs.

A UE may be within the coverage of multiple eNBs. One of these eNBs maybe selected to serve the UE. The serving eNB may be selected based onvarious criteria such as received power, path loss, signal-to-noiseratio (SNR), etc.

FIG. 3 shows a block diagram of a design of a base station/eNB 110 and aUE 120, which may be one of the base stations/eNBs and one of the UEs inFIG. 1. For a restricted association scenario, the base station 110 maybe the macro eNB 110 c in FIG. 1, and the UE 120 may be the UE 120 y.The base station 110 may also be a base station of some other type suchas an access point including a femtocell, a picocell, etc. The basestation 110 may be equipped with antennas 334 a through 334 t, and theUE 120 may be equipped with antennas 352 a through 352 r.

At the base station 110, a transmit processor 320 may receive data froma data source 312 and control information from a controller/processor340. The control information may be for the PBCH, PCFICH, PHICH, PDCCH,etc. The data may be for the PDSCH, etc. The processor 320 may process(e.g., encode and symbol map) the data and control information to obtaindata symbols and control symbols, respectively. The processor 320 mayalso generate reference symbols, e.g., for the PSS, SSS, andcell-specific reference signal. A transmit (TX) multiple-inputmultiple-output (MIMO) processor 330 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, and/or thereference symbols, if applicable, and may provide output symbol streamsto the modulators (MODs) 332 a through 332 t. Each modulator 332 mayprocess a respective output symbol stream (e.g., for OFDM, etc.) toobtain an output sample stream. Each modulator 332 may further process(e.g., convert to analog, amplify, filter, and upconvert) the outputsample stream to obtain a downlink signal. Downlink signals frommodulators 332 a through 332 t may be transmitted via the antennas 334 athrough 334 t, respectively.

At the UE 120, the antennas 352 a through 352 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) 354 a through 354 r, respectively. Eachdemodulator 354 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 354 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 356 may obtainreceived symbols from all the demodulators 354 a through 354 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 358 may process (e.g., demodulate,deinterleave, and decode) the detected symbols, provide decoded data forthe UE 120 to a data sink 360, and provide decoded control informationto a controller/processor 380.

On the uplink, at the UE 120, a transmit processor 364 may receive andprocess data (e.g., for the PUSCH) from a data source 362 and controlinformation (e.g., for the PUCCH) from the controller/processor 380. Theprocessor 364 may also generate reference symbols for a referencesignal. The symbols from the transmit processor 364 may be precoded by aTX MIMO processor 366 if applicable, further processed by the modulators354 a through 354 r (e.g., for SC-FDM, etc.), and transmitted to thebase station 110. At the base station 110, the uplink signals from theUE 120 may be received by the antennas 334, processed by thedemodulators 332, detected by a MIMO detector 336 if applicable, andfurther processed by a receive processor 338 to obtain decoded data andcontrol information sent by the UE 120. The processor 338 may providethe decoded data to a data sink 339 and the decoded control informationto the controller/processor 340.

The controllers/processors 340 and 380 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 340 and/orother processors and modules at the base station 110 may perform ordirect the execution of various processes for the techniques describedherein. The processor 380 and/or other processors and modules at the UE120 may also perform or direct the execution of functional blocks,and/or other processes for the techniques described herein. The memories342 and 382 may store data and program codes for the base station 110and the UE 120, respectively. A scheduler 344 may schedule UEs for datatransmission on the downlink and/or uplink.

In one configuration, the UE 120 for wireless communication includesmeans for detecting interference from an interfering base station duringa connection mode of the UE, means for selecting a yielded resource ofthe interfering base station, means for obtaining an error rate of aphysical downlink control channel on the yielded resource, and means,executable in response to the error rate exceeding a predeterminedlevel, for declaring a radio link failure. In one aspect, theaforementioned means may be the processor(s), the controller/processor380, the memory 382, the receive processor 358, the MIMO detector 356,the demodulators 354 a, and the antennas 352 a configured to perform thefunctions recited by the aforementioned means. In another aspect, theaforementioned means may be a module or any apparatus configured toperform the functions recited by the aforementioned means.

In accordance with one or more embodiments of the present disclosure,there are provided techniques for assignment of interference measurementresources in LTE. Assignment of LTE Rel-11 interference measurementresource may require careful network planning which may be undesirablein some cases. This disclosure presents a pseudo-random procedure toperform this assignment based on a (virtual) cell ID which avoids theneed for network planning.

LTE may support interference measurement on a newly introduced,dedicated resource. The dedicated resource is introduced as“Interference Measurement Resource (IMR)” in the LTE Rel-11specification. An IMR represents a set of resource elements (REs) onwhich the UE measures interference in an implementation-dependent way.An IMR may be given by a 4-port zero power channel state informationreference signal (ZP-CSI-RS) resource. The network may be responsiblefor ensuring that the interference created/measured on the IMR isrepresentative of the interference that the UE will encounter duringactual PDSCH transmissions. IMR allocation by the network may follow twoparadigms. In one paradigm, judicious assignment of IMRs may be based oncareful network planning. This may require significant planning effortbut may achieve superior performance as IMRs may be optimized forspecific interference hypotheses. In a second paradigm, assignment ofIMRs may be based on a randomized assignment without network planning.The assignment of IMRs may be based on a form of cell ID (detailsbelow). This assignment avoids the need for network planning. Goodperformance may be achieved as long as the assignment procedures avoidundesired overlap between IMRs.

Without randomization, an IMR may consist of the four resource elementsdefined by one ZP-CSI-RS resource. IMR assignment may be performed byselecting two ZP-CSI-RS resources and distributing the four resourceelements (REs) of the IMR among the eight resource elements (REs)defined by the two ZP-CSI-RS resources. Without deciding how theassignment of the four resource elements out of the eight resourceelements should be performed, there is a possibility that two IMRs mayoverlap by three or more resource elements (REs) which is undesirable.Further, signaling may need to be determined for the assignment of theIMRs.

To avoid these shortcomings, in an embodiment, assignment of IMRs may betied to a (virtual) cell ID. Also, it can be designed such that any twoIMRs may overlap by at most two resource elements (REs). This methodminimizes planning effort associated with IMRs. As noted above, theselection of the resource elements (REs) used for interferencemeasurement may be based on some form of cell ID. The possible optionsmay include:

each IMR could be associated with a new virtual cell ID (e.g., in therange from 0-503);

each IMR may use the same virtual cell ID as a non-zero power channelstate information reference signal (NZP-CSI-RS) with configured index;or

the IMR may use the physical cell ID of the serving cell (it is notedthat this may not be the preference in same-cell scenarios).

Time domain hopping may be beneficially employed with the selection ofresource elements changing on a per-subframe basis. The cell ID whichconfigures the IMR resource elements (as described above) may besubframe dependent, i.e., it may change from subframe to subframe. Thesequence of cell ID values may follow a signaled or predeterminedhopping pattern. Alternatively, the cell ID in a given subframe may bederived based on adding the subframe number (or some function thereof)to a signaled baseline cell ID (modulo the maximum range of cell IDs).Another design objective may be to minimize a worst-case overlap betweenIMR resource elements associated with different virtual cell IDs. Theembodiments herein target a worst case overlap of two resource elements(REs).

FIGS. 4A-C illustrate resource element assignments using a two stageprocess. Randomization of the IMR may consist of two stages. Illustratedin FIG. 4A is Stage 1, where two out of a total of ten ZP-CSI-RSresources are selected. In the example of FIG. 4A, ten ZP-CSI-RSresources from index zero through nine are shown. The two resources withindex values of 1 and 3 are selected. The two resources use the twoblocks of Pattern 2 (shown in FIG. 4B). Each ZP-CSI-RS resource isdefined by a block of four resource elements as in the LTEspecification. Picking two out of ten yields forty five differentcombinations (ten choose two). Illustrated in FIG. 4B is Stage 2, wherejudicious resource element assignment is performed. Judicious resourceelement assignment within the two selected ZP-CSI-RS resources accordingto the “codebook” as illustrated. No two pairs of patterns overlap bymore than two resource elements.

The construction of the Stage 2 patterns (as illustrated in FIGS. 4B-C)may be based on an enumeration. For example, the enumeration of oddnumbered patterns (i.e., Patterns 1, 3, 5, 7, 9, 11) may be defined by[AA], where A defines an assignment of two resources to a resourceblock. There are six possible ways of assigning two resources to aresource block with four resource elements (four choose two). [AA]defines two resource blocks with the sub-pattern A in a first (or left)resource block repeated in the second (or right) resource block. Forexample, the enumeration of even numbered patterns (i.e., Patterns 2, 4,6, 8, 10, 12) may be defined by [AĀ]. Ā is the complement or inversionof A. Thus, [AĀ] defines two resource blocks with the sub-pattern A in afirst (or left) resource block inverted in the second (or right)resource block. In the odd numbered patterns, there are 4 choose

${2\begin{pmatrix}4 \\2\end{pmatrix}\mspace{14mu}{combinations}} = {6\mspace{14mu}{\left( {{i.e.},\left( {1,2} \right),\left( {1,3} \right),\left( {1,4} \right),\left( {2,3} \right),\left( {2,4} \right),\left( {3,4} \right)} \right).}}$In the even numbered patterns, there are also 4 choose

${2\begin{pmatrix}4 \\2\end{pmatrix}\mspace{14mu}{combinations}} = 6.$The total number of odd and even numbered patterns is

${2 \times \begin{pmatrix}4 \\2\end{pmatrix}} = 12.$

The assignment process above may satisfy the design constraint of nomore than two resource elements overlapping. If the two out of tenpatterns selected in Stage 1 are not identical, then regardless of theStage 2 pattern selection, there cannot be more than two resourceelements overlapping (even if the Stage 2 patterns are the same). Thisis because for any of the Stage 2 patterns, each half contains only tworesource elements. If the two out of ten patterns selected in Stage 1are identical, then since any pair of two Stage 2 patterns has at mosttwo resource elements overlap, the constraint is also satisfied.

FIGS. 5A-B illustrate resource element assignments for two cells. Thefirst cell, in FIG. 5A, is selected for ZP-CSI-RS resources at index 1and 3, with Pattern 2 of FIG. 4B. The second cell, in FIG. 5B, isselected for ZP-CSI-RS resources at index 1 and 6, with Pattern 4 ofFIG. 4B. The Stage 1 selection for the first and second cells,therefore, has one common or overlapping block (resource at index 1).The ZP-CSI-RS resources may overlap in the resource index 1, asillustrated in FIG. 5C. In this example, one resource element (RE)overlaps in ZP-CSI-RS resources of index 1 (shown in ‘OVERLAP’ of FIG.5C). FIG. 5D illustrates an example where there is no overlap in Stage 1blocks, and FIG. 5E illustrates an example where both Stage 1 blocksoverlap.

In FIG. 5D, cells in the Stage 1 process selected two non-overlappingresource blocks. For example, a first cell selected resource blocks atindex 1 and 3. A second cell selected resource blocks at index 2 and 6.For Stage 2, the first cell selected Pattern 2, and the second cellselected Pattern 4. In this example, because the Stage 1 resource blocksdo not overlap, there may not be any overlapping resource elements forthe two cells. Thus, in cases where Stage 1 blocks are non-overlapping,no resource elements may overlap, and the constraint for no more thantwo overlapping resource elements is satisfied.

In FIG. 5E, cells in the Stage 1 process selected two overlappingresource blocks. For example, a first cell selected resource blocks atindex 1 and 3. A second cell selected resource blocks at index 1 and 3.For Stage 2, the first cell selected Pattern 2, and the second cellselected Pattern 4. In this example, both Stage 1 resource blocks (index1 and 3) overlap. If the resource elements within the blocks wererandomly selected, the resource elements may overlap by any number ofresource elements from zero to four. However, because the Stage 2resource elements are judiciously assigned as shown in Pattern 1 throughPattern 12 in FIGS. 4B and 4C, the resource elements in FIG. 5E may notoverlap by more than two resource elements. The resource block at index1 has an overlap at the top left corner. The resource block at index 3has an overlap at the bottom right corner. This results in an overlap ofonly two resource elements (REs), and the constraint for no more thantwo overlapping resource elements is satisfied.

The achievable reuse factor reflects the achievable degree ofrandomization. There are forty five Stage 1 patterns. There are twelveStage 2 patterns. The combination of the Stage 1 and Stage 2 patternsyields 45×12=540 possible options, which is greater than 504 (the cellID range). Thus, there may be more combinations of the resourceassignments than the range of cell IDs.

The mapping from a specific IMR virtual cell ID to a Stage 1 and Stage 2pattern may be performed through enumeration. For example, it is assumeda virtual cell ID=x. The index of the Stage 1 pattern is given by thefunction: floor(x/12). The floor function gives the largest integer notgreater than a value. For example, the floor of 2.5 is 2. The index ofthe Stage 2 pattern is given by the function: mod(x, 12). The modulo (ormod) function gives the remainder of a division operation. For example,8 mod 5 is 3. Further details of the disclosure are provided below.

The concept of an interference measurement resource (IMR) was introducedin Rel-11 to provide for dedicated resource elements on which the UE canbe configured to measure interference. IMR may consist of four resourceelements which, by default, consist of the four resource elements of aZP CSI-RS resource. Although a reuse factor of ten is achievable with ZPCSI-RS resources in a single subframe, a judicious assignment of IMRsbased on careful network planning may be important. An alternativeassignment approach may include the four resource elements of an IMRbeing distributed in a pseudo-random way over multiple ZP CSI-RSresources. The reuse factor may thus be increased dramatically whileconstraining the worst-case overlap between pseudo-randomly assignedIMRs. The objective is to avoid the need for cell planning.

There may be a specific way of performing this pseudo-random assignment.The proposal stated that the four resource elements of an IMR may bedistributed over two ZP-CSI-RS resources and that the resource elementassignment within those ZP CSI-RS resources would be pseudo-random. Moredetails are provided on how the assignment procedure could be performedbelow. For example, some form of cell ID may be introduced to serve as aseed for this pseudo-random assignment. Further, an example is providedof how the assignment within the selected two ZP-CSI-RS resource couldbe performed such that a worst-case overlap of two resource elements issatisfied. In particular, the following two-stage procedure may befollowed:

-   -   Stage 1: Pick two out of ten ZP-CSI-RS resources. This gives a        total of forty five different combinations (ten choose two).    -   Stage 2: Pick four resource elements out of the eight resource        elements defined by the selected two ZP CSI-RS resources. The        selection is performed by picking one of the twelve patterns        shown in FIGS. 4B-C.

The patterns (e.g., Pattern 1 through Pattern 12 illustrated in FIGS.4B-C) are constructed in a way that ensures that no more than tworesource elements overlap between any two patterns. Indeed, it is easyto see that the twelve patterns in FIGS. 4B-C satisfy this property. Asto the construction of the patterns, the following approach may be used.Starting from the six (namely four choose two) possible ways ofallocating two resource elements to a single ZP CSI-RS resource (say,the left group within each pattern) we construct the odd numberedpatterns by duplicating the pattern and the even numbered patterns bygrouping the left pattern with its inverted pattern. This yields a totalof twelve patterns which exhausts all possible ways of allocating RFssuch that no more than two resource elements overlap.

The reuse factor achievable by this assignment approach totals 540(=45×12) patterns which exceeds the total number of cell IDs, which maybe design constraint. Therefore, it seems natural to perform thepseudo-random assignment of the resources based on some form of “IMRcell ID,” either by introducing such a parameter explicitly or by tyingit to some existing (virtual) cell ID (e.g., the virtual cell IDassociated with one of the NZP CSI-RS resources). Assuming a given cellID x (with range 0<=x<=503), the RE allocation is given as follows:

-   -   Stage 1: The selection of the two out of ten resources is given        by enumerating all forty five combinations and selecting the one        with floor(x/12).    -   Stage 2: The index of the pattern selected as part of Stage 2 is        given by mod(x,12).

It may be seen that the assignment process satisfies the constraint ofno more than two resource elements (REs) overlapping between any twoIMRs with different cell ID. To see this, we use the following argument:

If the two out of ten patterns selected in Stage 1 are not identical,then regardless of the Stage 2 pattern, there cannot be more than tworesource elements overlap as each of the Stage 2 patterns occupies atmost two resource elements in each of the two ZP CSI-RS resources.

If the two out of ten patterns selected in Stage 1 are identical, thensince any pair of the two Stage 2 patterns has at most two resourceelements (REs) overlapping, the design constraint is also satisfied.

The present disclosure provides techniques and methods for assigninginterference measurement resources (IMRs) including the followingproposals. Adoption of the pseudo-random IMR assignment procedure mayavoid cell planning by tying the IMR allocation to some form or(virtual) cell ID. Selection of the IMR REs may be performed accordingto the two-step procedure outlined above which ensures a worst-caseoverlap of two resource elements (REs).

In accordance with one or more aspects of the embodiments describedherein, with reference to FIG. 6, there is shown a methodology 600,operable by a user entity, such as, for example, a UE, a terminal, amobile station, a subscriber unit, a station, or the like. Specifically,method 600 describes a procedure to measure interference resources. Themethod 600 may involve, at 602, receiving at least one identifierwherein the at least one identifier determines, at least in part, atleast one interference measurement resource that partially overlaps withanother at least one interference measurement resource. For example, theat least one interference measurement resource may include a number ofresource elements out of a set of resource elements. The method 600 mayinvolve, at 604, measuring interference based at least in part on the atleast one interference measurement resource.

With reference to FIG. 7, there is shown a methodology 700, operable bya network entity, such as, for example, a femtocell, a macrocell, apicocell, or the like. Specifically, method 700 describes a procedure toassign interference measurement resources. The method 700 may involve,at 702, transmitting an identifier of a network entity to at least onemobile entity, the identifier determining, at least in part, at leastone interference measurement resource that partially overlaps withanother at least one interference measurement resource. For example, theat least one interference measurement resource may include a number ofresource elements out of a set of resource elements. The method 700 mayinvolve, at 704, receiving channel state information (CSI) reports fromat least one mobile entity based on the at least one interferencemeasurement resource.

FIG. 8 shows an embodiment of an apparatus for measure interferenceresources, in accordance with the methodology of FIG. 6. With referenceto FIG. 8, there is provided an exemplary apparatus 800 that may beconfigured as a user entity (e.g., a UE, a terminal, a mobile station, asubscriber unit, a station, or the like) in a wireless network, or as aprocessor or similar device/component for use within the network entity.For example, apparatus 800 may be or may include UE 120 of FIG. 3. Theapparatus 800 may include functional blocks that may represent functionsimplemented by a processor, software, or combination thereof (e.g.,firmware). For example, apparatus 800 may include an electricalcomponent or module 802 for receiving at least one identifier whereinthe at least one identifier determines, at least in part, at least oneinterference measurement resource that partially overlaps with anotherat least one interference measurement resource. For example, electricalcomponent or module 802 may be configured for receiving the at least oneinterference measurement resource, where the least one interferencemeasurement resource comprises a number of resource elements out of aset of resource elements. Electrical component or module 802 may be, ormay include, means for receiving at least one identifier wherein the atleast one identifier determines, at least in part, at least oneinterference measurement resource that partially overlaps with anotherat least one interference measurement resource. Electrical component ormodule 802 may be, or may include at least one of antennas 352 a through352 r, or at least one of antennas 352 a through 352 r coupled to any ofreceive processor 358 and/or processor 380.

The apparatus 800 may include an electrical component or module 804 formeasuring interference based at least in part on the at least oneinterference measurement resource. Electrical component or module 804may be, or may include, means for measuring interference based at leastin part on the at least one interference measurement resource.Electrical component or module 804 may be, or may include at least oneof antennas 352 a through 352 r, or at least one of antennas 352 athrough 352 r coupled to any of receive processor 358 and/or processor380.

In related aspects, the apparatus 800 may optionally include a processorcomponent 850 having at least one processor, in the case of theapparatus 800 configured as a user entity (e.g., a UE, a terminal, amobile station, a subscriber unit, a station, or the like), rather thanas a processor. The processor 850, in such case, may be in operativecommunication with the components 802-804 via a bus 852 or similarcommunication coupling. The processor 850 may effect initiation andscheduling of the processes or functions performed by electricalcomponents 802-804.

In further related aspects, the apparatus 800 may include a radiotransceiver component 854. A stand alone receiver and/or stand alonetransmitter may be used in lieu of or in conjunction with thetransceiver 854. When the apparatus 800 is a network entity, theapparatus 800 may also include a network interface (not shown) forconnecting to one or more core network entities. The apparatus 800 mayoptionally include a component for storing information, such as, forexample, a memory device/component 856. The computer readable medium orthe memory component 856 may be operatively coupled to the othercomponents of the apparatus 800 via the bus 852 or the like. The memorycomponent 856 may be adapted to store computer readable instructions anddata for effecting the processes and behavior of the components 802-804,and subcomponents thereof, or the processor 850, or the methodsdisclosed herein. The memory component 856 may retain instructions forexecuting functions associated with the components 802-804. While shownas being external to the memory 856, it is to be understood that thecomponents 802-804 can exist within the memory 856. It is further notedthat the components in FIG. 8 may comprise processors, electronicdevices, hardware devices, electronic sub-components, logical circuits,memories, software codes, firmware codes, etc., or any combinationthereof.

FIG. 9 shows an embodiment of an apparatus for assigning interferencemeasurement resources, in accordance with the methodology of FIG. 7.With reference to FIG. 9, there is provided an exemplary apparatus 900that may be configured as a network entity (e.g., a femtocell, amacrocell, a picocell, or the like) in a wireless network, or as aprocessor or similar device/component for use within the network entity.For example, apparatus 900 may be, or may include, base station 110 ofFIG. 3. The apparatus 900 may include functional blocks that canrepresent functions implemented by a processor, software, or combinationthereof (e.g., firmware). For example, apparatus 900 may include anelectrical component or module 902 for transmitting an identifier of anetwork entity to at least one mobile entity, the identifierdetermining, at least in part, at least one interference measurementresource that partially overlaps with another at least one interferencemeasurement resource. For example, the at least one interferencemeasurement resource may include a number of resource elements out of aset of resource elements. Electrical component or module 902 may be, ormay include, means for transmitting an identifier of a network entity toat least one mobile entity, the identifier determining, at least inpart, at least one interference measurement resource that partiallyoverlaps with another at least one interference measurement resource.Electrical component or module 902 may be, or may include at least oneof antennas 334 a through 334 t, or at least one of antennas 334 athrough 334 t coupled to any of transmit processor 320 and/or processor340.

The apparatus 900 may include an electrical component or module 904 forreceiving channel state information (CSI) reports from at least onemobile entity based on the at least one interference measurementresource. Electrical component or module 904 may be, or may include,means for receiving channel state information (CSI) reports from atleast one mobile entity based on the at least one interferencemeasurement resource. Electrical component or module 904 may be, or mayinclude, at least one of antennas 334 a through 334 t, or at least oneof antennas 334 a through 334 t coupled to any of transmit processor 320and/or processor 340.

In related aspects, the apparatus 900 may optionally include a processorcomponent 950 having at least one processor, in the case of theapparatus 900 configured as a network entity (e.g., a femtocell, amacrocell, a picocell, or the like), rather than as a processor. Theprocessor 950, in such case, may be in operative communication with thecomponents 902-904 via a bus 952 or similar communication coupling. Theprocessor 950 may effect initiation and scheduling of the processes orfunctions performed by electrical components 902-904.

In further related aspects, the apparatus 900 may include a radiotransceiver component 954. A stand alone receiver and/or stand alonetransmitter may be used in lieu of or in conjunction with thetransceiver 954. When the apparatus 900 is a network entity, theapparatus 900 may also include a network interface (not shown) forconnecting to one or more core network entities. The apparatus 900 mayoptionally include a component for storing information, such as, forexample, a memory device/component 956. The computer readable medium orthe memory component 956 may be operatively coupled to the othercomponents of the apparatus 900 via the bus 952 or the like. The memorycomponent 956 may be adapted to store computer readable instructions anddata for effecting the processes and behavior of the components 902-904,and subcomponents thereof, or the processor 950, or the methodsdisclosed herein. The memory component 956 may retain instructions forexecuting functions associated with the components 902-904. While shownas being external to the memory 956, it is to be understood that thecomponents 902-904 can exist within the memory 956. It is further notedthat the components in FIG. 9 may comprise processors, electronicdevices, hardware devices, electronic sub-components, logical circuits,memories, software codes, firmware codes, etc., or any combinationthereof.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by ageneral purpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM.CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method of wireless communication, the methodcomprising: transmitting an identifier of a network entity to at leastone mobile entity, the identifier determining, at least in part, atleast one interference measurement resource that partially overlaps withanother at least one interference measurement resource, wherein the atleast one interference measurement resource comprises a number ofresource elements out of a set of resource elements; and receiving achannel state information (CSI) report from at least one mobile entitybased on the at least one interference measurement resource; wherein theidentifier is one of a virtual cell ID associated with the at least oneinterference measurement resource, an index pointing to the virtual cellID of a non-zero-power channel state information reference signal (NZPCSI-RS) resource in a Coordinated Multi-Point (COMP) measurement set, ora physical cell ID.
 2. The method of claim 1, wherein the at least oneinterference measurement resource overlaps by no more than two resourceelements with resource elements of the another at least one interferencemeasurement resource determined by another identifier of another networkentity.
 3. The method of claim 1, further comprising: selecting tworesource blocks from a set of resource blocks based, at least in part,on the identifier; and selecting four resource elements from the tworesource blocks based, at least in part, on the identifier, wherein thereceived CSI report is further based on the four resource elements. 4.The method of claim 1, wherein the identifier determines, at least inpart, at least one interference measurement resource based on anenumerated set of resource assignments.
 5. The method of claim 4,wherein the enumerated set of resource assignments comprises resourceassignments defined by a repetition of a sub-pattern.
 6. The method ofclaim 4, wherein the enumerated set of resource assignments comprisesresource assignments defined by an inversion of a sub-pattern.
 7. Themethod of claim 1, wherein the set of resource elements is associatedwith zero-power channel state information reference signal (ZP CSI-RS)resources.
 8. A wireless communication apparatus comprising: at leastone processor configured to: transmit an identifier of a network entityto at least one mobile entity, the identifier determining, at least inpart, at least one interference measurement resource that partiallyoverlaps with another at least one interference measurement resource,wherein the at least one interference measurement resource comprises anumber of resource elements out of a set of resource elements, andreceive a channel state information (CSI) report from at least onemobile entity based on the at least one interference measurementresource; and a memory coupled to the at least one processor for storingdata; wherein the at least one identifier is one of a virtual cell IDdefined for the at least one interference measurement resource, an indexpointing to the virtual cell ID of a non-zero-power channel stateinformation reference signal (NZP CSI-RS) resource in a CoordinatedMulti-Point (CoMP) measurement set, or a physical cell ID.
 9. Thewireless communication apparatus of claim 8, wherein the at least oneinterference measurement resource overlaps by no more than two resourceelements with resource elements of the another at least one interferencemeasurement resource determined by another identifier of another networkentity.
 10. The wireless communication apparatus of claim 8, wherein theat least one processor is further configured to: select two resourceblocks from a set of resource blocks based, at least in part, on theidentifier, and select four resource elements from the two resourceblocks, wherein the received CSI report is further based on the fourresource elements.
 11. The wireless communication apparatus of claim 8,wherein the identifier determines, at least in part, at least oneinterference measurement resource based on an enumerated set of resourceassignments.
 12. The wireless communication apparatus of claim 11,wherein the enumerated set of resource assignments comprises resourceassignments defined by a repetition of a sub-pattern.
 13. The wirelesscommunication apparatus of claim 11, wherein the enumerated set ofresource assignments comprises resource assignments defined by aninversion of a sub-pattern.
 14. A wireless communication apparatuscomprising: means for transmitting an identifier of a network entity toat least one mobile entity, the identifier determining, at least inpart, at least one interference measurement resource that partiallyoverlaps with another at least one interference measurement resource,wherein the at least one interference measurement resource comprises anumber of resource elements out of a set of resource elements; and meansfor receiving a channel state information (CSI) report from at least onemobile entity based on the at least one interference measurementresource; wherein the at least one identifier is one of a virtual cellID defined for the at least one interference measurement resource, anindex pointing to the virtual cell ID of a non-zero-power channel stateinformation reference signal (NZP CSI-RS) resource in a CoordinatedMulti-Point (COMP) measurement set, or a physical cell ID.
 15. Thewireless communication apparatus of claim 14, wherein the at least oneinterference measurement resource overlaps by no more than two resourceelements with resource elements of the another at least one interferencemeasurement resource determined by another identifier of another networkentity.
 16. The wireless communication apparatus of claim 14, furthercomprising: means for selecting two resource blocks from a set ofresource blocks based, at least in part, on the identifier, and meansfor selecting four resource elements from the two resource blocks,wherein the received CSI report is further based on the four resourceelements.
 17. The wireless communication apparatus of claim 14, whereinthe identifier determines, at least in part, at least one interferencemeasurement resource based on an enumerated set of resource assignments.18. The wireless communication apparatus of claim 17, wherein theenumerated set of resource assignments comprises resource assignmentsdefined by a repetition of a sub-pattern.
 19. The wireless communicationapparatus of claim 17, wherein the enumerated set of resourceassignments comprises resource assignments defined by an inversion of asub-pattern.
 20. A non-transitory computer-readable medium comprisingcode for causing at least one computer to: transmit an identifier of anetwork entity to at least one mobile entity, the identifierdetermining, at least in part, at least one interference measurementresource that partially overlaps with another at least one interferencemeasurement resource, wherein the at least one interference measurementresource comprises a number of resource elements out of a set ofresource elements; and receive a channel state information (CSI) reportfrom at least one mobile entity based on the at least one interferencemeasurement resource; wherein the at least one identifier is one of avirtual cell ID defined for the at least one interference measurementresource, an index pointing to the virtual cell ID of a non-zero-powerchannel state information reference signal (NZP CSI-RS) resource in aCoordinated Multi-Point (CoMP) measurement set, or a physical cell ID.21. The non-transitory computer-readable medium of claim 20, wherein theat least one interference measurement resource overlaps by no more thantwo resource elements with resource elements of the another at least oneinterference measurement resource determined by another identifier ofanother network entity.
 22. The non-transitory computer-readable mediumof claim 20, wherein the computer-readable medium further comprises codefor causing the at least one computer to: select two resource blocksfrom a set of resource blocks based, at least in part, on theidentifier, and select four resource elements from the two resourceblocks, wherein the received CSI report is further based on the fourresource elements.
 23. The non-transitory computer-readable medium ofclaim 20, wherein the identifier determines, at least in part, at leastone interference measurement resource based on an enumerated set ofresource assignments.
 24. The non-transitory computer-readable medium ofclaim 23, wherein the enumerated set of resource assignments comprisesresource assignments defined by a repetition of a sub-pattern.
 25. Thenon-transitory computer-readable medium of claim 23, wherein theenumerated set of resource assignments comprises resource assignmentsdefined by an inversion of a sub-pattern.